Question

I would like to add a index for quick lookups and uniqueness for a column called “Username”. I see an option to choose UNIQUE or INDEX. Should I create both, or just go with UNIQUE?

I am not using username as a primary key guys.

Answer 1

UNIQUE creates an INDEX automatically for most dbs. So to answer you, you should create just one, which is UNIQUE. You can find a relevant thread here for MySQL